Passcodes are a series of characters that are entered by a user to provide a form of authentication of a user. Passcodes may be used in a wide range of situations to protect websites, applications, remote services, financial services, etc. Passcodes are often referred to as passwords, however the term passcode is used herein to make it clear that the passcode may be formed of or include numbers and other characters as well as letters. The term passcode therefore includes personal identification numbers (PINs).
A passcode is a knowledge factor of authentication as it is something the user knows. Two-factor authentication is often used which requires something a user has and something a user knows. For example, a user may have a bankcard and may know a PIN.